You can use sealant tape on cracks that have developed on window joints. Although small, these crack can let heat escape, and during the winter months, this air can increase your heating bills. Applying sealant tape is one quick and easy—though temporary—solution you can use for this type of problem.
Step 1 - Locate Crack
Cracks are usually visible when you look closely on the window joints. There will be times that you can hear a low hum or whistle when you get closer to the crack. This is due to air coming in the cracks, especially on a windy day.
Step 2 - Clean the Window and Window Frame
To ensure that the sealant tape will adhere well, clean the window with a rag and cleaning solution. Remove all dirt, debris and grease.
Step 3 - Apply Sealant Tape
Gently put the tape over the cracks, and press down firmly.
Step 4 - Paint the Tape to Match the Window Frame
Depending on the color of the window joint or window frame, paint over the tape so that it blends well and will not be too obvious.